American Chemical Society
Entropy and Enthalpy Changes
My room isn't messy — it's a scientific experiment in entropy! Scholars investigate entropy, enthalpy, and spontaneity through a guided procedure and set of questions. The lesson connects the Second Law of Thermodynamics, energy...
American Chemical Society
Energy and Entropy of a Stretched Rubber Band
Stephen Perry invented and patented the modern rubber band in 1845. Young scientists put his discovery to work as they use rubber bands to observe entropy and enthalpy. They determine the change in free energy to figure out if it...
Teach Engineering
Efficiency of a Water Heating System
Tired of waiting for hot water? Groups of three determine the efficiency of an electric water-heating device. They calculate the amount of energy it takes to heat the water and the theoretical amount of energy required to heat the water....